For a period of time last year I worked for a hosting provider in the marketing department. They tasked me with explaining the concept of bandwidth for the corporate blog, but they never used it. As I’ve been gone for the better part of a year, I figured I might share it without issue.
In the past, you could only watch entertainment when and where the providers said, in front of your TV via terrestrial cable at a prescribed time. At the same time, gaming was primarily an offline pursuit. Because media consumption is now on-demand, on location, over the Internet, and 24/7, hosting customers are finding their own customers eating through bandwidth far more quickly than they did a few years ago, and that quickly scalable hosting infrastructures will be more and more important.
Some stats: In 2011, more than 100 million Americans watched online video content each day, a 43% increase over the previous year. At the beginning of 2012, more than 11% of all digital traffic was consumed over smartphones and tablets; a year later that number had jumped to 21%. In addition, mobile device penetration is increasing fast. In Australia, the US and the UK, smart phone user penetration topped 50%. This is expected to be true in most of western Europe by 2014.
In this blog we’ll talk about what bandwidth means and how video, gaming, and advancements in mobile internet are driving bandwidth consumption.
What Do We Mean When We Talk About Bandwidth
In the context of web or data infrastructure hosting, we’re really talking about two things:
- An amount of data traffic going over the network, usually measured in bytes (kB, MB, GB). When a hosting company offers “unlimited bandwidth” it means the amount of data traffic served is limited only by the port’s capacity.
In general, the term “unlimited” has been replaced with the more accurate “unmetered”. - The rate at which data travels over the network as measured in bits per second (kbps, Mbps, Tbps).
On an unmetered port, your data traffic limit is calculated by multiplying the rate of the port (in bits) by the number of seconds in the period you want to discuss and dividing by 8 because traffic is measured in bytes, but port capacity is measured in bits. By this measurement, the daily traffic limit on an unmetered 1 Gb port should be 10.8 TB.
However, maximum port traffic generally runs 80-90% of maximum capacity. This 10-20% overhead includes bandwidth used by the communication protocol and transactions at other hardware and software layers of network communication.
So, when an article or report asserts that consumer demand for bandwidth is increasing, it refers to:
- Demand for data, generally from the consumer including on-demand streaming media (YouTube, Netflix, Spotify), audio and video downloads (Amazon, iTunes, Bandcamp), gaming (World of Warcraft), voice over IP, and IPTV.
- Consumer demand for higher mobile and fixed broadband data rates
- Supplier demand for networks with greater capacity, servers with greater processing power, and more storage.
Three things currently drive bandwidth consumption:
- 24/7 entertainment on demand
- Increased image quality
- 3G and 4G mobile internet usage
Media consumption
Customers are no longer constrained by television network calendars. Entertainment providers must now address around-the-globe demands 24/7. Later on I’ll discuss improvements in mobile networks that enable greater connectivity and more entertainment on the go.
Image quality, compression, and a little secret
Adding to consumer bandwidth demand are improvements in image quality. This boils down to four things: color depth (the number of bits per pixel of an image), frame rate (the number of images per second), resolution, and compression. If you want to stream video, multiply the first three and then take into account video compression, to get your bandwidth requirement.
Resolution, expressed in megapixels (Mpx), is calculated by multiplying the number of pixels wide an image is by the number of rows in the image.
- Standard Definition (SD) – 418,560 (~0.4 Mpx)
- High Definition (HD) – 921,600 pixels (~0.9 Mpx)
- Full High Definition (FHD) – 2,073,600 (~2.1 Mpx)
- Ultra-High Definition (UHD) 4K – ~8.3 Mpx
- Ultra-High Definition (UHD) 8K – ~33.2 Mpx
FHD and UHD are the wave of the future. As you can see, each step up in resolution increases the file size approximately four fold.
A 16-bit SD video clip requires about 167 Mbps of bandwidth. A 16-bit full HD clip requires almost 830 Mbps – a huge jump! Only one user might be able to stream this uncompressed video via your 1 Gb port, though that user would probably still suffer some latency.
Compression attempts to reduce file size and maintain quality by discarding parts of frames that don’t change from a baseline frame, discarding frequencies less visible to the human eye, and by grouping values that are almost the same as being the same.
Most video content uses compression to shrink file size, but that doesn’t change the fact that you want to be able to serve content to as many viewers as possible.
When you just need to scale fast, here’s a quick and dirty way to calculate what you need: Taking into account that media are usually compressed, just take the file size and divide it by the runtime.
For example, divide a 24,000 megabit (3 gigabyte) movie file by 6,000 seconds (100 minutes) to get a required bandwidth of 4 Mbps. A 1 Gb port with 20% overhead could support 200 concurrent streams of this file.
For streaming audio, you can divide the port capacity by the bit rate to get the number of concurrent users, for example. 800 Mbps / 192 kbps = 800,000/192 = ~4160 concurrent users.
Shall we play a game?
A 2013 NPD survey of US online gamers found 6% spend more time gaming in 2013 than they did in 2012. In addition, online gaming on mobile devices was up 12% over 2012 figures. Research by eMarketer estimates that there were 102 million mobile gamers in the US in 2012 and this number should rise to 121 million in 2013 and to 174 million by 2016, a 75% leap in four years.
Console, mobile, social, and online role playing games (RPGs) all contribute to the rise in gaming-related bandwidth consumption, but one of the main gaming bandwidth hogs is client downloads. Gaming client software can run from two to 20 GB per download.
Game-play at the player level is requiring less bandwidth than it used to. Cloud gaming allows direct streaming of the game from the server to the gamer’s computer (or mobile device). While these games require greater processing power at the server end, they use less bandwidth per player.
But I shot that orc! Why won’t he die?
No matter how much processing power a games server has, once there are hundreds or thousands of users, bandwidth obviously becomes a factor, and its requirements are calculated in a similar way to that discussed above. Most action games, however, require very low latency as well. Latency is the aggregate (in milliseconds) of delays incurred processing network data. For reliable game play action games require that the time taken to connect to the server when a shot is fired is kept to an absolute minimum.
Is that for here or to go?
And the last thing driving the explosion in bandwidth is mobile phone capability. Internet access via mobile first became possible with 2.5G digital networks.
Under 2.5G, mobile phones could use WAP and MMS for basic email, text, and web access, but even the best connection speeds were only about twice traditional dialup (115 kbps), assuming you were in a populated area. In addition, few web sites were optimized for pre-smartphone displays, much less for streaming video and gaming.
With the advent of 3G and its support for data rates of 200 kbit/s, more aspects of life could move online. Social networking tools like whatsapp, LinkedIn, and Facebook; mobile TV, Video on Demand, and GPS, not to mention online shopping, now find a place on most smart mobile devices. 3G made the first leap towards true anywhere/anytime mobile entertainment access possible.
While it’s fast, however, there are some things for which it is not fast enough. The 4G specification calls for 1 Gbps data rates – sufficient to support HD mobile television. With good connections, it might even support FHD.
3G and 4G Penetration
By the end of 2012, almost 1.6 billion users worldwide connected via 3G. One forecast suggests that 85% of the world’s population will be connected via 3G by 2017.
Another estimate suggests that more than one third of mobile connections in the Asia Pacific region will be 4G by 2016 and in Europe by 2020. That’s a lot of high-speed connections.
Conclusion
With that many mobile high-speed connections, entertainment, (as we noted at the beginning) will be truly be anytime, anywhere and with more avenues for delivering higher quality images, sounds, games, and communications.
Joe Jots 